Recently, a light emitting diode (LED) is spotlighted as a light emitting device. Since the LED can convert electric energy into light energy with high efficiency and long life span of about 5 years or more, the LED can remarkably reduce the energy consumption and repair and maintenance cost. In this regard, the LED is spotlighted in the next-generation lighting field.
Such an LED is prepared as a light emitting semiconductor layer including a first conductive semiconductor layer, an active layer and a second conductive semiconductor layer, in which the active layer generates light according to current applied thereto through the first and second conductive semiconductor layers.
Meanwhile, since a material constituting the light emitting semiconductor layer has a refractive index lower than that of external air, light generated from the active layer is not effectively emitted to the outside, but totally reflected from a boundary surface and extinguished at an inside of the light emitting semiconductor layer.
To solve this problem, a concave-convex light extracting structure is formed on the first conductive semiconductor layer or the second conductive semiconductor layer provided at one side of the active layer. However, the electrical characteristics of the LED may be degraded due to the light extracting structure.